Abstract: A gerotor motor having an inner gerotor positioned within an outer gerotor, a housing radially surrounding the outer gerotor, a cover plate positioned adjacent the outer gerotor and pressure balance grooves extending between the outer gerotor/cover plate interface and a region of radial clearance between the outer gerotor and the housing. Three such balance grooves are disclosed. They include an inlet balance groove, an outlet balance groove and an axial balance groove. These grooves serve to balance axial and radial hydraulic pressure forces acting on the outer gerotor. The resulting net pressure force is substantially independent of both inlet and outlet pressure.